USE OF POTASSIUM PYROANTIMONATE IN THE LOCALIZATION OF SODIUM IONS IN RAT KIDNEY TISSUE

Potassium pyroantimonate added to fixative solutions has been used in tissue localization of sodium ions. The distribution and specificity of the resulting precipitate in rat kidney is described in this study. Two reproducible patterns of precipitate were obtained in control tissues. The first pattern, which occurred after fixation in solutions containing aldehyde, showed the precipitate to be mainly extracellular. The second pattern, showing the precipitate in both intracellular and extracellular locations, occurred after aldehyde fixation in those experimental situations favoring cellular swelling or after fixation with solutions containing osmium tetroxide. It appeared that sodium ions could move after fixation but that sodium pyroantimonate precipitate could not. Since model systems demonstrated that dense precipitate formed when potassium pyroantimonate was added to solutions containing certain biological amines or some divalent cations, it appeared likely that the reagent did not provide specific tissue localization for sodium ions.     

RADIOACTIVITY AND PHYSIOLOGICAL ACTION OF POTASSIUM

1. The non-radioactive cesium ion can replace the potassium ion almost quantitatively in solutions required for the development of the egg of the sea urchin into swimming blastulæ. 2. Thorium chloride and uranium acetate cannot replace the potassium chloride in the solutions required for the development of the egg. 3. Thorium chloride and uranium acetate do not antagonize the action of the potassium contained in sea water upon the development of eggs.     

ADAPTATION OF CUTANEOUS TACTILE RECEPTORS : VI. INHIBITORY EFFECTS OF POTASSIUM AND CALCIUM

1. Both solutions of Ringer plus fifteen times the normal K content, and solutions of Ringer plus fifteen times the normal Ca content markedly hasten the adaptation of single freely branching axon endings in frog''s skin to repetitive air puff stimuli. 2. The K effect is produced more rapidly than is that of Ca. The K effect is reversible by washing with Ringer''s solution, while the Ca effect is not. The Ca inhibition can, however, be reversed and recovery effected by washing with K rich solutions. 3. Evidence is discussed which indicates that Ca probably plays no rôle in normal adaptation, and the experiments are interpreted as substantiating the hypothesis of adaptation due to K.     

THE SELECTIVE ABSORPTION OF POTASSIUM BY ANIMAL CELLS : I. CONDITIONS CONTROLLING ABSORPTION AND RETENTION OF POTASSIUM.

1. Individual variations in the potassium content of the fresh muscles of frogs are notable even when computed as percentages of the dry solids. The potassium content averaged higher in freshly collected summer frogs than in winter frogs after a period of captivity. 2. Muscles show a loss of from 8 to 15 per cent of their potassium during perfusion with potassium-free Ringer solution but tenaciously hold the remainder. 3. Muscles, stimulated to contract under conditions that do not produce irreversible stages of fatigue, show losses of potassium no greater than those attributable to the presence of a potassium-free medium. 4. A condition favorable to the taking up of potassium probably occurs in a contracting muscle because rubidium and cesium, substances very similar to potassium in chemical and physiological behavior, are absorbed in retainable form by a contracting muscle but not by a resting one.     

THE SELECTIVE ABSORPTION OF POTASSIUM BY ANIMAL CELLS : II. THE CAUSE OF POTASSIUM SELECTION AS INDICATED BY THE ABSORPTION OF RUBIDIUM AND CESIUM.

1. Frog muscles perfused with Ringer solution in which potassium chloride has been replaced by an equivalent amount of rubidium or cesium chloride take up rubidium or cesium and incorporate them into the tissue substance in such form as to be retained during a subsequent perfusion with potassium-free Ringer solution, provided the muscles contract during the first perfusion. Retention of rubidium or cesium by a resting muscle does not occur. 2. Rats on synthetic diets, adequate in all respects except that potassium was replaced by an equivalent amount of rubidium or cesium, died after a period varying from 10 to 17 days with characteristic symptoms including tetanic spasms. Muscle, heart, liver, kidney, spleen, and lung tissues were then found to contain significant amounts of rubidium or cesium. The concentration of these metals in the muscle amounted, in some cases, as shown by a spectroscopic estimation, to about half the concentration of potassium normally found in mammallian muscle. 3. The results are regarded as tending to confirm the theory that the peculiarities in the physiological effects of potassium, including the facility with which it is "selected" by living cells in preference to sodium, are related to the electronic structure of the potassium ion as compared with that of similar ions. The possible relationship of the comparative migration velocity, a function of the electronic structure, to physiological effects is suggested.     

THE POTASSIUM UPTAKE OF LACTOBACILLUS ACIDOPHILUS

SUMMARY: A reproducible flame speetrophotometric method for the determination of the potassium uptake of Lactobacilius acidophilus is described. The potassium uptake curve was characteristic and had a coefficient of variation between replicate samples at peak uptake of approximately 2%. Two general applications of the technique have been demonstrated: the evaluation of the toxicity of an inhibitory substance (fluoride as sodium fluoride), and determination of the effect of the interaction of L. acidophilus and L. casei in a mixed culture.     

THE POTASSIUM EQUILIBRIUM IN MUSCLE

1. Analyses were made of the K and HCO₃ content, the irritability, and weight change of isolated frog sartorius muscles after immersion for 5 hours in Ringer''s solutions modified as to pH and potassium content. 2. At each pH a concentration of potassium in the solution was found which was in diffusion equilibrium with the potassium in the muscle. In greater concentrations potassium moved into the muscle against the concentration gradient and vice versa. 3. The greater the alkalinity of the solution the smaller the concentration of the potassium at equilibrium so that the product of the concentrations of OH and K in the solution at equilibrium tends to remain approximately constant. 4. The pH inside the muscle is approximately equal to that outside when first dissected but it tends to change during immersion so as to follow the changes in the pH of the solution. This finding is in direct conflict with the theory according to which the high potassium concentration inside should be accompanied by an equally high hydrogen ion concentration in relation to that outside. 5. The diffusion of potassium into the muscle makes its contents more alkaline but the increase in alkalinity is not always, nor usually, equivalent to the amount of potassium which has diffused and conversely, the pH inside can change in either direction according to the pH outside without there being any diffusion of potassium. Hence potassium is not the only penetrating ion. 6. The irritability of the muscles is at a maximum in concentrations of potassium which are greater than that in normal Ringer''s solution, or about 20 mg. per cent potassium. This optimum does not seem to be a function of pH and is therefore not dependent upon the direction of movement of the potassium but probably on the ratio of potassium outside to that inside. 7. Swelling of the muscles occurs in solutions which injure the muscle so as to permit both cations and anions to enter without permitting the organic protein anions to escape. Anion impermeability is necessary to prevent this same osmotic swelling under normal conditions. 8. An increase in the CO₂ tension in muscle and solution causes a greater increase in acidity in the solution than in the muscle and leads to a loss of potassium. One expects therefore a potassium shift from tissues to blood comparable to the chlorine shift from plasma to corpuscles.     

THE IMPORTANCE OF POTASSIUM AFTER OPERATION

A deficiency of potassium in a patient after operation is manifest clinically by anorexia, malaise, apathy, weakness, abdominal distention and hypochloremia.Many patients who have had a prolonged disturbance in nutrition may have a “subclinical” hypopotassemia.Prophylaxis by means of replacement of the potassium excreted daily in the urine is the ideal treatment.When the clinical picture of potassium deficit develops, the amount of the potassium ion needed for replacement should be calculated on the basis of the total amount of water in the body of the patient.     

ON GUAIACOL SOLUTIONS : I. THE ELECTRICAL CONDUCTIVITY OF SODIUM AND POTASSIUM GUAIACOLATES IN GUAIACOL

1. Measurements on the densities, viscosities, dielectric constants, and specific conductances of pure anhydrous and water-saturated guaiacol at 25°C. are reported. 2. The solubility of water in guaiacol at 25°C., and its effect on the electrical conductivity of a sodium guaiacolate solution is given. 3. Electrical conductivity measurements are reported on solutions of sodium and potassium guaiacolates in water-saturated guaiacol at 25°C. 4. The decrease of electrical conductivity with increasing concentration for these salts is explained on the basis of an ionic equilibrium combined with the interionic attraction theory of Debye and Hückel. 5. The limiting equivalent conductances of sodium and potassium guaiacolates in water-saturated guaiacol at 25°C., the corresponding limiting ionic mobilities, and the dissociation constants are computed from the conductivity measurements. The salts are found to be weak electrolytes with dissociation constants of the order of 5 x 10^–6.     

EFFECTS OF POTASSIUM ON THE POTENTIAL OF HALICYSTIS

Sea water in which sodium has been replaced by potassium produces about the same degree of negativity in Halicystis and in Valonia. With increasing dilution of this sea water up to 1 ÷ 16 the degree of negativity steadily falls off in Halicystis. This differs from the situation in Valonia where Damon finds that with increasing dilution the negativity passes through a minimum after which increasing dilution produces increasing negativity. But conditions in the two organisms differ so greatly that a comparison is of rather doubtful significance.     

A FURTHER STUDY OF THE TOXICITY OF POTASSIUM CYANIDE TO RAINBOW TROUT (SALMO GAIRDNERII RICHARDSON)

The distributions of the periods of survival of individual rainbow trout in solutions of potassium cyanide are asymmetrical and approximately log-normal within the range of concentration where the relation between log time and log concentration is linear, whereas they are symmetrical and approximately normal at higher concentrations.
Some inherent, persistent features possessed by the fish influence survival time in both the higher and lower ranges of concentration, but other such features exert a significant influence only in the lower concentrations.
Some of the features influencing survival time in the lower concentration range only, are associated with body size.     

THE ACTION OF POTASSIUM CYANIDE AND POTASSIUM FERRICYANIDE ON CERTAIN RESPIRATORY PIGMENTS

The oxygen in hemoglobin is liberated by K₃Fe(CN)₆ and not by KCN, that in hemocyanin by KCN and not by K₃Fe(CN)₆, that in hemerythrin by both, and that in echinochrome by K₃Fe(CN)₆ and not by KCN. The bearing of these results on the nature of the substances involved is discussed.     

THE ACCUMULATION OF ELECTROLYTES : IV. INTERNAL VERSUS EXTERNAL CONCENTRATIONS OF POTASSIUM

Lowering the potassium in the sea water from 0.011 M to 0.006 M caused an exit of potassium from cells of Valonia macrophysa. Sodium continued to penetrate and the ratio K ÷ Na fell off. The cells ceased to grow but there was no evidence of injury. Increasing the external potassium brought about an increase of the internal concentration of potassium, of halide, of total cations, and of the ratio K ÷ Na inside. These phenomena are to be expected on theoretical grounds.     

SOME CHEMICAL ASPECTS OF THE POTASSIUM EFFECT

The ability of Nitella to distinguish electrically between Na⁺ and K⁺ (potassium effect) appears to depend on several organic substances (or groups of substances). Of these R_MK and R_SK determine the mobility and partition coefficient (S) respectively of K⁺ while R_MNa and R_SNa do the same for Na⁺. These substances can vary independently and this variation is susceptible to experimental control.     

MECHANICAL RESTORATION OF IRRITABILITY AND OF THE POTASSIUM EFFECT

Treatment of Nitella with distilled water apparently removes from the cell something which is responsible for the normal irritability and the potassium effect, (i.e. the large P.D. between a spot in contact with 0.01 M KCl and one in contact with 0.01 M NaCl). Presumably this substance (called R) is partially removed from the protoplasm by the distilled water. When this has happened a pinch which forces sap out into the protoplasm can restore its normal behavior. The treatment with distilled water which removes the potassium effect from the outer protoplasmic surface does not seem to affect the inner protoplasmic surface in the same way since the latter retains the outwardly directed potential which is apparently due to the potassium in the sap. But the inner surface appears to be affected in such fashion as to prevent the increase in its permeability which is necessary for the production of an action current. The pinch restores its normal behavior, presumably by forcing R from the sap into the protoplasm.     

THE RADIOACTIVITY OF POTASSIUM FROM HUMAN SOURCES

A comparison of the radioactivity of potassium from human and commercial sources indicates that the radioactive isotope K⁴⁰ is probably 1 or 2 per cent less abundant in human potassium.